Various known sensor devices and methods have been utilized to detect different types of target molecules or particulates. Certain sensors involve detection or measurement of biological elements utilizing antibody-antigen interactions. With these types of biological sensors, a surface or sensor can be labeled such that highly specific responses to molecules of interest can be generated. While such sensors may have high specificity, they may also have a number of limitations including inadequate sensitivity and limited applications, particularly in the context of gas or vapor detection. For example, such biological sensors may be suitable for detecting certain gas or vapor molecules that have synthetically matched antibodies (such as Trinitrotoluene or “TNT”), but most gas or vapor molecules do not involve matched antibodies and the same degree of surface specificity.
Emission and absorption spectroscopic techniques may appear to be suitable methods for use in gas or vapor detection since they provide a “chemical fingerprint” of individual molecules in a mixture. However, such systems and methods have limited sensitivities for detection of a number of gas or vapor molecules and particulates of interest.
Other known sensors and detection methods also involve limited specificity, sensitivities and/or limited applications such that they are not suitable or are not satisfactory for various gas or vapor sensing applications. In addition to these limitations, response times of sensors suitable for use in gas or vapor environments are often slow, particularly following exposure to high concentrations of a gas or vapor.